1. Field of the Invention
The present invention relates to a recording tape cartridge rotatably accommodating a single reel, around which a recording tape such as a magnetic tape is wound.
2. Description of the Related Art
Conventionally, magnetic tape cartridges have been known in which a magnetic tape, which is used as a data recording/playback medium of a computer or the like, is wound on a single reel, and the reel is accommodated within a case. A leader member, which is a leader pin, a leader tape, or a leader block, for example, is provided at the distal end of the magnetic tape. A pull-out means provided at a drive device pulls out the leader member from an opening of the magnetic tape cartridge, and the magnetic tape fixed to the leader member is wound onto a take-up reel of the drive device.
A reel gear is carved in a ring shape at the center of the bottom surface of the reel which emerges from an opening formed in the bottom surface of the magnetic tape cartridge. Due to a driving gear, which is provided at a rotating shaft of the drive device, meshing with the reel gear, the reel is driven to rotate. Further, due to the reel of the magnetic tape cartridge and the take-up reel of the drive device being rotated synchronously, data can be recorded onto the magnetic tape or data recorded on the magnetic tape can be played back.
A large amount of information can be recorded in this magnetic tape cartridge, although little space is needed to accommodate the magnetic tape cartridge when it is stored. As shown in FIGS. 10 through 12, the position of the opening of the magnetic tape cartridge and the type of door for opening and closing the opening differ in accordance with the type of the leader member. Namely, in the case of a leader pin 108, as shown in FIG. 10, an opening 104 is formed in a side wall 102A of a case 102 which side wall 102A is parallel to the direction of loading the magnetic tape cartridge into a drive device (the direction of arrow A). The opening 104 is opened and closed by a door 106 which slides in the same direction as the loading direction.
However, if the opening 104 is provided at the side wall 102A of the case 102 in this way, the pull-out means of the drive device must pull the leader pin 108 out from the left-right lateral direction of the case 102 (i.e., non-rectilinearly). Thus, space for the pull-out means to move around the case 102 must be ensured in the left-right lateral direction of the case within the drive device, and the mechanism for moving the pull-out means around (i.e., non-rectilinearly) becomes complex. In other words, the drawback arises that the drive device becomes large. Moreover, there is the problem that the path along which a magnetic tape T is pulled out becomes long.
Further, in the case of a leader tape T, as shown in FIG. 11, an opening 116 is formed in a front wall 114A of a case 114 which front wall is orthogonal to the direction of loading the magnetic tape cartridge into a drive device (the direction of arrow A). A door 118, which opens and closes the opening 116, is a pivoting-type door which pivots toward the front around a shaft supported in a vicinity of a corner of the case 114. However, if the opening 116 is provided at the front wall 114A of the case 114 in this way, although there is no need for the pull-out means of the drive device to move non-rectilinearly, the door 118 opens over a wide area toward the front. Therefore, space must be ensured within the drive device such that nothing interferes with the door 118 when the opening 116 is to be opened. In short, a drawback arises in that the drive device becomes large.
Moreover, in the case of a leader block 126, as shown in FIG. 12, an opening 124 is formed by diagonally cutting off a corner portion of the front side of the case in the direction of loading the magnetic tape cartridge into the drive device. The opening 124 is opened and closed directly by the leader block 126. However, if the opening 124 is opened and closed by the leader block 126 in this way (namely, if the leader block 126 also functions as the door for opening and closing the opening), a problem arises in that it is easy for the leader block 126 to become scratched or dirtied. Specifically, the leader block 126 fits together with a reel hub 130 of the drive device and forms a portion of the reel hub 130. Thus, if a scratch is formed in or dirt adheres to the leader block 126, even if the scratch or dirt is a scratch or dirt which is not problematic when the leader block 126 is ordinarily used as the door, it may become difficult for the leader block 126 to fit-together with the reel hub 130, and there is the possibility that problems in the moving of the magnetic tape T may arise.
Further, since the leader block 126 forms a part of a winding surface for winding the magnetic tape T, the above-described damage or contamination may damage the data recorded on the magnetic tape T or may create damaged areas on the magnetic tape T where data cannot be recorded.
Furthermore, since the leader block 126 is merely anchored at the edge of the opening 124, the leader block 126 may come off when the case 122 is dropped. Moreover, since the size of the leader block 126 is larger than the size of the leader pin, many constraints are imposed on the form of the case 122.
In view of the aforementioned, an object of the present invention is to provide a recording tape cartridge in which an opening, which is adapted to minimize a distance of a path for drawing out a recording tape, can be opened or closed by a shielding member, which allows to reduce a space in a drive for accommodating the cartridge, without interfering with a reel and a leader member, as well as a structure of an opening/closing device of the drive, which operates the shielding member to open or close the opening, can be simplified.
In order to accomplish the above-described object, a recording tape cartridge according to the invention comprises: a rectangular case; an opening through which a leader member is drawn out; a shielding member for opening and closing the opening; and a handling portion disposed at an end portion of the shielding member. The case rotatably accommodates a single reel, around which a recording tape is wound. The opening is formed by notching one of corner portions of the case at a side coming first when the case is mounted in the drive, and the leader member is attached at an end of the recording tape. The shielding member is disposed at the case, and one of ends of the shielding member is movable outside side walls of the case along a mounting direction in which the case is mounted in the drive. The shielding member is movable along the mounting direction while engaging with the opening/closing member of the drive during an operation to mount the case in the drive.
Since the opening is formed by notching the corner of the rectangular case at the side coming first when the case is mounted, an open plane is oriented in the mounting direction in which the case is mounted in the drive as well as in a direction perpendicular to the mounting direction. In other words, the open plane is inclined with respect to the mounting direction. Therefore, a drawing device can access the leader member in the mounting direction, in the direction perpendicular to the mounting direction, or from a side of the corner of the case, i.e., in a direction perpendicular to the inclined open plane.
This allows a design of the drive in which a distance of a path for drawing out the recording tape is minimized. Further, since there is no need of a driving mechanism for driving the drawing device so as to move around to hold or fix the leader member, a compact and low-cost drive can be designed.
Further, since the one end portion of the shielding member moves outside the side wall of the case along the mounting direction to open or close the opening which is inclined with respect to the mounting direction, in other words, since the shielding member moves around the outside of the leader member and the reel while rotating around the one end portion thereof to open or close the opening, a range of movement (a track of movement) of the shielding member does not extend, by an mount exceeding its thickness, beyond the notched portion of the case being notched for forming the opening (if the notched portion is not provided, an outline area of the rectangular case).
Therefore, a space in the drive for accommodating the recording tape cartridge is small, and the track of movement of the shielding member does not interfere with the leader member and the reel in the case. Further, since the shielding member moves outside the case, an inside structure of the case can be simplified.
In addition, by disposing the opening/closing member of the drive so that it can engage with the handling portion disposed at the one end portion of the shielding member and movable along the mounting direction, the opening can be opened simply through the operation of mounting the recording tape cartridge (the case) in the drive, and this allows to simplify a structure of the opening/closing device including the opening/closing member. Moreover, since the shielding member, including the handling portion disposed thereto, moves outside the side wall of the case, there is no need of an opening (such as a slit) for exposing the handling portion so as to be movable to the outside of the case, as there is in a structure in which the shielding member moves within the case, and dust-tightness of the case can be increased with a simple structure.
As described above, in the recording tape cartridge of the invention, the opening, which is adapted to minimize a distance of a path for drawing out the recording tape, can be opened or closed by the shielding member, which allows reduction in a space in the drive for accommodating the cartridge, without interfering with the reel and the leader member, and a structure of the opening/closing device of the drive, which operates the shielding member to open or close the opening, can be simplified.
When the distance of the path for drawing out the recording tape is minimized as described above, a path of the recording tape is also shortened. This allows a reduction in a contact abrasion between the recording tape and a tape guide. Further, as described above, when the opening is formed by notching the corner portion of the case, a range of accessible directions of the drawing device to the leader member is widened. Therefore, a range of possible positions of the leader member in the case is widened, thereby increasing a degree of freedom in designing the drive. Since the shielding member operates as described above, the possible positions of the leader member are not affected by the shielding member, that is, the range of the possible positions of the leader member is not narrowed.
Since the shielding member is provided separately from the leader member which is drawn out from the case and need not be removed from the case, it can be designed so as not to easily come off with a drop impact. When the recording tape is not used, the leader member is accommodated in the case whose opening is closed by the shielding member, and therefore is not likely to be damaged or dirtied. Therefore, it does not affect drawing or running of the recording tape in the drive, and does not damage the recording tape.